We've added manual tags support to our OPC device driver. This feature is a rescue in case of legacy OPC servers that do not support items browsing. Simply add desired item IDs to the 'Manual Items' device property and these items will be directly requested from the device upon each synchronization. Manual tags will be available at the device configuration, next to auto-discovered tags if any.
The full list of available device drivers is available in Protocols/Drivers section on our website.